Dysregulation of circulating autoantibodies against VEGF-A, VEGFR-1 and PlGF in preeclampsia - A role in placental and vascular health?

Systematic design and evaluation of aptamers for VEGF and PlGF biomarkers of Preeclampsia

Preeclampsia is a potentially life-threatening condition for both mother and baby, characterized by hypertension and potential organ damage. Early diagnosis is crucial to mitigate its adverse health effects. Traditional diagnostic methods, which focus on late-manifesting symptoms like hypertension and proteinuria, underscore the need for molecular diagnostic approaches for timely detection. This study successfully designs and evaluates novel aptamers with high specificity and affinity for Vascular Endothelial Growth Factor (VEGF) and Placental Growth Factor (PlGF), biomarkers closely associated with preeclampsia. Using molecular docking, molecular dynamics simulations, and BioLayer Interferometry (BLI), we identified aptamers that demonstrated strong binding affinities, comparable or superior to traditional antibodies. Our findings suggest that these aptamers have the potential to be integrated into cost-effective, point-of-care diagnostic tools, significantly improving early detection and intervention strategies for preeclampsia. The robust performance of these aptamers marks a pivotal step toward the development of more reliable and accessible diagnostic solutions, with implications for better maternal and fetal health outcomes.

Fetal-origin cells in maternal circulation correlate with placental dysfunction, fetal sex, and severe hypertension during pregnancy

Fetal microchimerism (FMc) arises when fetal cells enter maternal circulation, potentially persisting for decades. Increased FMc is associated with fetal growth restriction, preeclampsia, and anti-angiogenic shift in placenta-associated proteins in diabetic and normotensive term pregnancies. The two-stage model of preeclampsia postulates that placental dysfunction causes such shift in placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFLt-1), triggering maternal vascular inflammation and endothelial dysfunction. We investigated whether anti-angiogenic shift, fetal sex, fetal growth restriction, and severe maternal hypertension correlate with FMc in hypertensive disorders of pregnancy with new-onset features (n = 125). Maternal blood was drawn pre-delivery at > 25 weeks' gestation. FMc was detected by quantitative polymerase chain reaction targeting paternally inherited unique fetal alleles. PlGF and sFlt-1 were measured by immunoassay. We estimated odds ratios (ORs) by logistic regression and detection rate ratios (DRRs) by negative binomial regression. PlGF correlated negatively with FMc quantity (DRR = 0.2, p = 0.005) and female fetal sex correlated positively with FMc prevalence (OR = 5.0, p < 0.001) and quantity (DRR = 4.5, p < 0.001). Fetal growth restriction no longer correlated with increased FMc quantity after adjustment for correlates of placental dysfunction (DRR = 1.5, p = 0.272), whereas severe hypertension remained correlated with both FMc measures (OR = 5.5, p = 0.006; DRR = 6.3, p = 0.001). Our findings suggest that increased FMc is independently associated with both stages of the two-stage preeclampsia model. The association with female fetal sex has implications for microchimerism detection methodology. Future studies should target both male and female-origin FMc and focus on clarifying which placental mechanisms impact fetal cell transfer and how FMc impacts the maternal vasculature.

Vasoregulatory Autoantibodies and Clinical Outcome After Ischemic Stroke-PROSCIS-B

BACKGROUND

Vasoregulatory autoantibodies including autoantibodies targeting G-protein-coupled receptors might play a functional role in vascular diseases. We investigated the impact of vasoregulatory autoantibodies on clinical outcome after ischemic stroke.

METHODS AND RESULTS

Data were used from the PROSCIS-B (Prospective Cohort With Incident Stroke-Berlin). Autoantibody-targeting receptors such as angiotensin II type 1 receptor (AT1R), endothelin-1 type A receptor, complement factor-3 and -5 receptors, vascular endothelial growth factor receptor-1 and -2, vascular endothelial growth factor A and factor B were measured. We explored associations of high antibody levels with (1) poor functional outcome defined as modified Rankin Scale >2 or Barthel Index <60 at 1 year after stroke, (2) Barthel Index scores over time using general estimating equations, and (3) secondary vascular events (recurrent stroke, myocardial infarction) or death up to 3 years using Cox proportional hazard models. We included 491 patients with ischemic stroke with data on autoantibody levels and outcome. In models adjusted for demographics and vascular risk factors, high autoantibody concentrations (quartile 4) targeting complement factor C3a receptor, vascular endothelial growth factor receptor-2, and vascular endothelial growth factor B were associated with poor functional outcome at 1 year: (odds ratio, 2.0 [95% CI, 1.1-3.6]; odds ratio, 1.8 [95% CI, 1.1-3.2]; and odds ratio, 2.1 [95% CI, 1.2-3.6], respectively) and with lower Barthel Index scores over 3 years (complement factor C3a receptor: adjusted β=-3.3 [95% CI, -5.7 to -0.5]; VEGF-B: adjusted β=-2.4 [95% CI, -4.8 to -0.06]). Patients with high autoantibody levels were not at higher risk for secondary vascular events or death.

CONCLUSIONS

High levels of autoantibodies against vascular endothelial growth factor receptor-2, vascular endothelial growth factor B, and complement factor C3a receptor measured are associated with poor functional outcome after stroke but not with recurrent vascular events or death.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01363856.

Vascular endothelial growth factor-C and its receptor-3 signaling in tumorigenesis

The cancer-promoting ligand vascular endothelial growth factor-C (VEGF-C) activates VEGF receptor-3 (VEGFR-3). The VEGF-C/VEGFR-3 axis is expressed by a range of human tumor cells in addition to lymphatic endothelial cells. Activating the VEGF-C/VEGFR-3 signaling enhances metastasis by promoting lymphangiogenesis and angiogenesis inside and around tumors. Stimulation of VEGF-C/VEGFR-3 signaling promotes tumor metastasis in tumors, such as ovarian, renal, pancreatic, prostate, lung, skin, gastric, colorectal, cervical, leukemia, mesothelioma, Kaposi sarcoma, and endometrial carcinoma. We discuss and update the role of VEGF-C/VEGFR-3 signaling in tumor development and the research is still needed to completely comprehend this multifunctional receptor.

Poor glucose control and markers of placental dysfunction correlate with increased circulating fetal microchimerism in diabetic pregnancies

Fetal microchimerism (FMc) arises during pregnancy as fetal cells enter maternal circulation and remain decades postpartum. Circulating FMc is increased in preeclampsia, fetal growth restriction, and as we recently showed, is associated with biomarkers of placental dysfunction in normotensive term pregnancies. Diabetes mellitus (DM) also correlates with placental dysfunction. We hypothesize that poor glucose control and markers of placental dysfunction are associated with increased circulating FMc in diabetic pregnancies. We included 122 pregnancies preceding active labor (pregestational DM, n = 77, gestational DM (GDM), n = 45) between 2001 and 2017. Maternal and fetal samples were genotyped for various human leukocyte antigen (HLA) loci, and other polymorphisms to identify fetus-specific alleles. We used validated polymerase chain reaction (PCR) assays to quantify FMc in maternal peripheral blood buffy coat. Negative binomial regression with adjustment for confounders was used to assess FMc quantity. In pregestational DM, increased circulating FMc correlated with elevation of HbA1c (≥ 6.0 %) (detection rate ratio (DRR) = 4.9, p = 0.010) and a 1000 pg/mL rise in the anti-angiogenic biomarker soluble fms-like tyrosine kinase-1 (sFlt-1) (DRR = 1.1, p = 0.011). In GDM, increased FMc correlated with elevated 2-hour oral glucose tolerance test results (DRR = 2.3, p = 0.046) and birthweight < 10th or > 90th percentile (DRR = 4.2, p = 0.049). These findings support our novel hypothesis that FMc correlates with poor glucose control and various aspects of placental dysfunction in DM. Whether increased FMc in pregnancies with poor glucose control and placental dysfunction contributes to the risk of preeclampsia in diabetic pregnancies and to the increased risk of chronic cardiovascular disease later in life remains to be investigated.

Serum amyloid A1 and pregnancy zone protein in pregnancy complications and correlation with markers of placental dysfunction

BACKGROUND

Hypertensive disorders of pregnancy (preeclampsia, gestational hypertension, and chronic hypertension), diabetes mellitus, and placental dysfunction confer an increased risk of long-term maternal cardiovascular disease. Preeclampsia is also associated with acute atherosis that involves lesions of uteroplacental spiral arteries, resembling early stages of atherosclerosis. Serum amyloid A1 is involved in hypercoagulability and atherosclerosis and may aggregate into amyloid-aggregations of misfolded proteins. Pregnancy zone protein may inhibit amyloid aggregation. Amyloid is involved in Alzheimer's disease and cardiovascular disease; it has been identified in preeclampsia, but its role in preeclampsia pathophysiology is unclear.

OBJECTIVE

We hypothesized that serum amyloid A1 would be increased and pregnancy zone protein decreased in hypertensive disorders of pregnancy and diabetic pregnancies and that serum amyloid A1 and pregnancy zone protein would correlate with placental dysfunction markers (fetal growth restriction and dysregulated angiogenic biomarkers) and acute atherosis.

STUDY DESIGN

Serum amyloid A1 is measurable in both the serum and plasma. In our study, plasma from 549 pregnancies (normotensive, euglycemic controls: 258; early-onset preeclampsia: 71; late-onset preeclampsia: 98; gestational hypertension: 30; chronic hypertension: 9; diabetes mellitus: 83) was assayed for serum amyloid A1 and pregnancy zone protein. The serum levels of angiogenic biomarkers soluble fms-like tyrosine kinase-1 and placental growth factor were available for 547 pregnancies, and the results of acute atherosis evaluation were available for 313 pregnancies. The clinical characteristics and circulating biomarkers were compared between the pregnancy groups using the Mann-Whitney U, chi-squared, or Fisher exact test as appropriate. Spearman's rho was calculated for assessing correlations.

RESULTS

In early-onset preeclampsia, serum amyloid A1 was increased compared with controls (17.1 vs 5.1 µg/mL, P<.001), whereas pregnancy zone protein was decreased (590 vs 892 µg/mL, P=.002). Pregnancy zone protein was also decreased in diabetes compared with controls (683 vs 892 µg/mL, P=.01). Serum amyloid A1 was associated with placental dysfunction (fetal growth restriction, elevated soluble fms-like tyrosine kinase-1 to placental growth factor ratio). Pregnancy zone protein correlated negatively with soluble fms-like tyrosine kinase-1 to placental growth factor ratio in all study groups. Acute atherosis was not associated with serum amyloid A1 or pregnancy zone protein.

CONCLUSION

Proteins involved in atherosclerosis, hypercoagulability, and protein misfolding are dysregulated in early-onset preeclampsia and placental dysfunction, which links them and potentially contributes to future maternal cardiovascular disease.

The physiological and pathological functions of VEGFR3 in cardiac and lymphatic development and related diseases

Vascular endothelial growth factor receptors (VEGFRs) are part of the evolutionarily conserved VEGF signalling pathways that regulate the development and maintenance of the body's cardiovascular and lymphovascular systems. VEGFR3, encoded by the FLT4 gene, has an indispensable and well-characterized function in development and establishment of the lymphatic system. Autosomal dominant VEGFR3 mutations, that prevent the receptor functioning as a homodimer, cause one of the major forms of hereditary primary lymphoedema; Milroy disease. Recently, we and others have shown that FLT4 variants, distinct to those observed in Milroy disease cases, predispose individuals to Tetralogy of Fallot, the most common cyanotic congenital heart disease, demonstrating a novel function for VEGFR3 in early cardiac development. Here, we examine the familiar and emerging roles of VEGFR3 in the development of both lymphovascular and cardiovascular systems, respectively, compare how distinct genetic variants in FLT4 lead to two disparate human conditions, and highlight the research still required to fully understand this multifaceted receptor.

Pregnancy and postpartum levels of circulating maternal sHLA-G in preeclampsia

Preeclampsia is a leading cause of maternal and offspring mortality and morbidity, and predicts increased future cardiovascular disease risk. Placental dysfunction and immune system dysregulation are likely key pathophysiological factors. Soluble human leukocyte antigen G (sHLA-G) may dampen the specific immune response towards placental trophoblasts. Previous studies have shown low sHLA-G levels in preeclampsia, but postpartum, levels are unknown. Furthermore, the relationship between sHLA-G and sFlt-1 and PlGF, placental function markers, is unknown. We hypothesized that low maternal sHLA-G during pregnancy would be associated with placental dysfunction, including preeclampsia, gestational hypertension, and dysregulated sFlt-1 and PlGF, and that sHLA-G would remain decreased following preeclampsia. We included 316 pregnant women: 58 with early-onset preeclampsia (<34 weeks' gestation), 81 with late-onset preeclampsia (≥34 weeks' gestation), 25 with gestational hypertension, and 152 normotensive controls. Postpartum (1 or 3 years), we included 321 women: 29 with early-onset preeclampsia, 98 with late-onset preeclampsia, 57 with gestational hypertension, and 137 who were normotensive during their index pregnancies. In pregnancy, plasma sHLA-G was significantly lower both in the early- and late-onset preeclampsia groups compared to controls. In women with preeclampsia or gestational hypertension, sHLA-G was inversely correlated with serum sFlt-1. Postpartum, plasma sHLA-G levels were significantly higher in women who had had early-onset preeclampsia compared to controls. Our results support that sHLA-G may be important for placental function. Unexpectedly, sHLA-G was elevated up to 3 years after early-onset preeclampsia, suggesting an excessively activated immune system following this severe preeclampsia form, potentially contributing to future cardiovascular disease risk.

Different Polymorphisms of Vascular Endothelial Growth Factor Gene in Patients with Pre-Eclampsia among The Iranian Women Population

Background

Pre-eclampsia (PE) is a pregnancy complication and one of the leading causes of maternal and neonatal morbidity and mortality in the world. PE is characterized by high blood pressure and signs of damage to the other organs, most often the liver and kidneys. Given the importance of mutation in the vascular endothelial growth factor (VEGF) gene and its correlation with the incidence of PE, the relationship of VEGF encoding gene polymorphisms rs922583280, rs3025040 and rs10434 with the incidence of PE in the population of Iranian women was studied, in this research.

Materials and Methods

In this case-control study, 100 pregnant women with PE diagnosis and 50 healthy pregnant women were evaluated using Sanger sequencing method to determine genotypes rs922583280, rs3025040 and rs10434.

Results

There was no significant difference in the allele frequency of rs922583280 and rs3025040 polymorphisms between case and control groups (P>0.05), while frequency of the recessive allele (G) for rs10434 polymorphism was significantly higher in the case group compared to the control group (P=0.014, case=24%, control=12%). Frequency of the allele A in the control group was higher than the patient group (case=76%, control=88%). Frequency of AG genotype in the patient group was also higher than the control group. In addition, frequency of AA genotype in the control group was higher than the patient group (case=57%, control=78).

Conclusion

The results of this study demonstrated a significant difference between patient and control groups for the VEGF coding gene polymorphism rs10434 and it can affect the incidence of PE among Iranian women.

Hypertension: Focus on autoimmunity and oxidative stress

Understanding the causal role of the immune and inflammatory responses in hypertension has led to questions regarding the links between hypertension and autoimmunity. Immune pathology in primary hypertension mimics several autoimmune mechanisms observed in the pathogenesis of systemic lupus erythematosus, psoriasis, systemic sclerosis, rheumatoid arthritis and periodontitis. More importantly, the prevalence of hypertension in patients with these autoimmune diseases is significantly increased, when compared to control populations. Clinical and epidemiological evidence is reviewed along with possible mechanisms linking hypertension and autoimmunity. Inflammation and oxidative stress are linked in a self-perpetuating cycle that significantly contributes to the vascular dysfunction and renal damage associated with hypertension. T cell, B cell, macrophage and NK cell infiltration into these organs is essential for this pathology. Effector cytokines such as IFN-γ, TNF-α and IL-17 affect Na⁺/H⁺ exchangers in the kidney. In blood vessels, they lead to endothelial dysfunction and loss of nitric oxide bioavailability and cause vasoconstriction. Both renal and vascular effects are, in part, mediated through induction of reactive oxygen species-producing enzymes such as superoxide anion generating NADPH oxidases and dysfunction of anti-oxidant systems. These mechanisms have recently become important therapeutic targets of novel therapies focused on scavenging oxidative (isolevuglandin) modification of neo-antigenic peptides. Effects of classical immune targeted therapies focused on immunosuppression and anti-cytokine treatments are also reviewed.